1. Field of the Invention
The present invention relates to a printing apparatus and a method of controlling the printing apparatus.
2. Description of the Related Art
A print system is conventionally known in which a print request from a host apparatus is once received by a higher level apparatus provided separately from a printing apparatus, and in accordance with the received print request, print image data generated by the higher level apparatus are transmitted via a data transfer path to the printing apparatus, and the printing apparatus prints the print image data.
On the other hand, a print control apparatus for controlling print operation in the printing apparatus needs to execute print operation with timing appropriate for the print process. Accordingly, a technique is already known, in which a print system for printing print image data transferred from the above higher level apparatus buffers print image data transferred from a higher level apparatus to memory of a printer engine, and a data control unit successively reads the print image data used for printing from the memory and transfers the print image data to a print unit.
Japanese Patent Application Laid-open No. 2008-183884 discloses a print system having a data control unit for sorting image data in units of ink ejection for the purpose of increasing data transfer speed. More specifically, in Japanese Patent Application Laid-open No. 2008-183884, the data control unit sorts image data transferred from the host apparatus to the printer controller for each unit of ink ejection, in accordance with nozzle arrangement of a matrix-type head of an ink jet method. Accordingly, during printing, the memory control and the data transfer can be processed at a high speed.
However, in the conventional technique using a data transfer method for transferring the print image data read by the data control unit from the memory directly to the print unit, it is difficult to change a combination of the data control units and the print units handling the same color in one print system. Therefore, when this data transfer method is used to achieve a print system capable of changing a combination of the data control units and the print units handling the same color with a model of the printer engine, there is a problem in that it is necessary to design each data control unit in accordance with the combination of the data control units and the print units.
In Japanese Patent Application Laid-open No. 2008-183884, the print image data are transferred to the print unit on the basis of the order suitable for printing. However, the configuration of Japanese Patent Application Laid-open No. 2008-183884 is such that one line of data stored in the line memory are sorted to be suitable for the two-dimensional matrix-type head, and when the combination of the data control units and the print units handling the same color, there is a problem in that it is necessary to design the data control unit in accordance with the combination of the data control units and the print units, which problem has not yet been solved by Japanese Patent Application Laid-open No. 2008-183884.
Therefore, there is a need to easily support many variations in a print system for transferring print image data to a printing apparatus from a higher level apparatus